A randomization code was generated by an independent statistician who did not participate in the study nor visit the study site. The randomization code was then placed in an opaque and sealed envelope and sent a copy to the pharmacist in the study centre so that he got to know what to put in each envelope for study participants. The envelopes were kept by the study pharmacist who dispensed the drugs. The code was to be broken when the principal investigator felt that the blinded treatment was harmful to the patient, either because of the side effects or failure to respond in which case he would urgently notify the data safety and review board with the view of breaking the code for that particular patient.